Taxometrics in psychopathology research: an introduction to some of the procedures and related methodological issues

This article introduces a special section on the use of taxometrics to examine the categorical versus the dimensional structure of various forms of psychopathology. Paving the way into the special section, this introduction briefly describes 3 taxometric methods--mean above minus below a sliding cut (MAMBAC), maximum covariation (MAXCOV), and maximum eigenvalue (MAXEIG)--and discusses possible threats to statistical conclusion validity that often emerge when such techniques are applied in psychopathology research.     

Testing mediational models with longitudinal data: questions and tips in the use of structural equation modeling

R. M. Baron and D. A. Kenny (1986; see record 1987-13085-001) provided clarion conceptual and methodological guidelines for testing mediational models with cross-sectional data. Graduating from cross-sectional to longitudinal designs enables researchers to make more rigorous inferences about the causal relations implied by such models. In this transition, misconceptions and erroneous assumptions are the norm. First, we describe some of the questions that arise (and misconceptions that sometimes emerge) in longitudinal tests of mediational models. We also provide a collection of tips for structural equation modeling (SEM) of mediational processes. Finally, we suggest a series of 5 steps when using SEM to test mediational processes in longitudinal designs: testing the measurement model, testing for added components, testing for omitted paths, testing the stationarity assumption, and estimating the mediational effects.     

The long-term effect of high- and low-rate responding histories on fixed-interval responding in rats

Tell rats were given extended lever-press training on a fixed-interval (FI) 30-s food reinforcement schedule from the outset or following exposure to one or two previous reinforcement schedules. For 4 rats the previots schedule was either fixed-ratio 20, which generated high response rates, or differential-reinforcement-of-low-rate 20 s, which produced low response rates. For 4 additional rats the extended training on FI 30 s was preceded by experience with two schedules: fixed-ratio 20 followed by differential-reinforcement-of-low-rate 20 s; or the same two schedules in the reverse order. Fixed-interval response rates were initially affected by the immediately preceding schedule, but after 80 to 100 sessions, all traces of prior schedule history had disappeared. The results also showed no long-term effect of schedule history on the interfood-interval patterns of responding on the FI 30-s schedule. These results support one of the most central tenets of the experimental analysis of behavior: control by the immediate consequences of behavior.     

Aesthetic Truth and Pastoral Theology: A Proposal for a New Method of Reflection and Practice

Pastoral theology needs to clarify its identity as an autonomous theological discipline by developing its own knowledge base, body of research, and practice methods. It needs to broaden its scope to include not only a concern for personal issues, but also larger sociocultural and anthropological ones as well. Additionally, there is a pressing need for moving beyond the confines of traditional methods of correlation. This essay offers a new method for pastoral theological reflection and practice that is grounded in Hans-Georg Gadamer's understanding of aesthetic truth and hermeneutics. It offers a new way of conceptualizing the relationship of pastoral theology to such conversation partners as the Bible and theological tradition, the social sciences, and practical wisdom, demonstrating how these can contribute to the pastoral theological task.     

K-ABC simultaneous processing, DAS nonverbal reasoning, and Horn's expanded fluid-crystallized theory.

Horn's distinction between--fluid intelligence (Gf) and visualization (Gv) was investigated with two Nonverbal Reasoning subtests from the Differential Ability Scales and three Simultaneous Processing subtests from the Kaufman Assessment Battery for Children. The sample comprised a predominantly Euro-American groups of 57 normal boys and girls between the ages of 6 and 12 years. Principal factor analysis yielded clear-cut Gf and Gv dimensions. The Gf factor was composed both of Differential Ability Scales and Kaufman-ABC subtests, suggesting that the construct of simultaneous processing is not merely a measure of Gv, as researchers have hypothesized, but also measures Horn's Gf fluid intelligence to a considerable extent.     

A longitudinal study of negative affect and self-perceived competence in young adolescents.

In a 4-wave, 2-year longitudinal design, the authors obtained measures of negative affect (NA) and self-perceived competence from 220 boys and 216 girls who were 7th graders at the beginning of this study. NA was operationalized as the common dimension underlying self-reports of depressive symptoms, anxiety symptoms, and negative emotions. Self-perceived competence consisted of 2 higher order constructs: a well-behaved/good-student factor and an attractive/athletic/popular factor. Structural equation modeling revealed very high stability estimates for all constructs. Nevertheless, self-perceived competence in the attractive/athletic/popular domain predicted changes in NA. Conversely, NA predicted changes in self-perceived competence in the well-behaved/good-student domain. The primacy of NA versus self-cognitions depends, in part, on the type of self-cognitions being examined.     

The influence of semantic relationships on older adult map memory

Research has shown that nonspatial features, including semantic categories, can bias younger adults' spatial location memory. For example, semantically related information is remembered as being closer in space than semantically unrelated information (Hirtle & Mascolo, 1986). These findings suggest that verbal information is concurrently encoded with spatial information and influences younger adults' spatial information retrieval. The present study explored whether older adults have a similar dependency between verbal and spatial information. In Experiment 1, older and younger adults learned maps depicting semantically categorizable landmarks. After learning, participants completed landmark free recall and distance estimation tasks. Younger adults recalled more landmarks from semantically organized maps compared with older adults. In addition, younger adults were more likely to underestimate the distance between semantically related landmarks than were older adults. Experiment 2 examined whether supportive instructions would influence older adults' use of verbal information when learning maps. When given instructions that encouraged semantic feature use, older adults remembered more landmarks, were more likely to cluster landmarks semantically, and demonstrated biases in distance estimation based on semantic relationships. These findings suggest that verbal influences on spatial/map learning in older adults depends on explicit instructions or environmental support at encoding. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Human sensitivity to the magnitude and probability of a continuous causal relation in a video game

Continuous causation, in which incremental changes in one variable cause incremental changes in another, has received little attention in the causal judgment literature. A video game was adapted for the study of continuous causality in order to examine the novel cues to causality that are present in these paradigms. The spatial proximity of an object to an "enemy detector" produced auditory responses as a function of the object's proximity. Participants' behavior was a function of the range of the effect's auditory sensitivity and the moment-to-moment likelihood of detection. This new paradigm provides a rich platform for examining the cues to causation encountered in the learning of continuous causal relations.     

The unique contributions of the facilitation of procedural memory and working memory to individual differences in intelligence

Individual differences in working memory account for a substantial portion of individual differences in complex cognitive processes (e.g., comprehension) and fluid intelligence. However, a large portion of the variance in fluid intelligence and comprehension is unexplained. The current investigation was conducted to evaluate whether individual differences in the facilitation of procedural memory accounts for unique variance in intelligence not accounted for by working memory. To measure variability in the facilitation of procedural memory, we used a task that required participants to first classify exemplars of two categories; facilitation was then operationalized by subsequent improvements in the speed of classifying new exemplars from those categories (i.e., an operation-specific memory procedure). Three measures of each focal construct (facilitation in procedural memory, working memory, comprehension and fluid intelligence) were administered to 256 participants. We used structural equation modeling to examine the relationships among these latent variables. Working memory did account for variance in fluid intelligence and comprehension, but most important, individual differences in facilitation of procedural memory accounted for unique variance in fluid intelligence and comprehension.